Quartz crystal oscillator



May 21, 1935. a R, BECHMANN 2,002,167

QUARTZ CRYSTAL OSCILLATOR Filed July 8, 1955 12:9 10' E159. ib

INVENTOR RUDOLF BECH ANN BY .M-M/Q AT'I'ORNEY Patented May 21, 1935UNITED STATES QUARTZ CRYSTAL OSCILLATOR Rudolf Bechmann, Berlin,Germany, assignor to Telefunken Gesellschait fiir DrahtloseTelegraphic-m. b. 11., Berlin, Germany, a corporation of GermanyApplication July 8, 1933, Serial No. 679,504

In Germany 16 Claims.

This invention relates to certain improvements upon a quartz crystaloscillator arrangement and particularly to apparatus having temperatureregulating means confined within an evacuated vessel such as disclosedin German Patent No.

552,771. An object of this invention is to simplify and improve quartzcrystal oscillators and is directed particularly to the means ofsupporting the crystal which is retained within a holder or setting thatis confined within an evacuated vessel. In such apparatus for holdingquartz crystals Whenever very high frequency stability is required it isnecessary, on the one hand, to dispose the quartz crystal in a way andunder circumstances as free from damping as possible, while, on theother hand, it should be fixed mechanically so that absolutely constantsupporting is insured, seeing that no matter how slight the movement ofthe crystal inside its setting means, this will infallibly occasion moreor less change in the frequency.

In order to secure such a condition, the quartz crystal, according tothe present invention is so attached in lts supporting or setting meansthat the surfaces or faces of the oscillating quartz crystal will notcontact the electrodes. In fact, the crystal is so set inside asupporting annulus between points in such a way that, when in itsneutral zone, i. e., in the central or median plane of the quartzcrystal it will be held under conditions free from damping.

The drawing shows the invention in a number of exemplified embodiments.

Fig. 1a is an elevation partly in section of a crystal having acontinuous groove for retaining the crystal.

Fig. 1b is a plan view of a crystal having three notches for retainingthe crystal.

Fig. 2 is a plan view partly in section of the crystal retaining ringhaving a single spring.

Fig. 2a is a detailed showing of the leaf spring for flexibly retainingthe crystal.

Fig. 2b is a sectional view of the crystal retaining ring having threesprings.

Fig. 3 is a sectional view of the complete quartz crystal oscillatorarrangement.

In the form of construction illustrated in Fig. 1a the crystal has inits median plane a circumferential groove or notch. Instead of this, asshown in Fig. 1b, a plurality of tiny holes may be formed peripherallyabout the crystal. The supporting is then insured, for example, by meansof three peaks or prongs engaging in the said groove or in the holes ordepressions formed in the crystal.

July 22, 1932 Figs. 2, 2a. and 21) show the several ways of securing orsetting of a quartz crystal Q in a manner as just described by the aidof the three peaks or prongs engaging in the said groove or in the holesor depressions formed in the crystal.

Referring now in detail to Fig. 2 there is shown the securing or settingof a quartz crystal Q by the aid of the three peaks or points Si, S2, S3in a holder ring R. The said pea-ks may be united by screwing in thesetting system fixedly or elastically. In the case of Fig. 2, forinstance, only one of the said peaks, S3, is secured upon the leafspring by the agency of which it is pressed against the crystal.

Fig. 3 shows a section laid through the assembly of crystal supportermeans of the kind suited to be inserted into the vacuum vessel. Thesetting or holder means F which as disclosed in the parent German PatentNo. 552,771, supports the heating winding WI and the measuring orcalibrated winding W2 contains the quartz crystal Q which is held in thering R as before described. E denotes the electrodes which are so set inthe quartz that they will not directly touch the crystal. The holdingring R and the electrodes E are stayed in reference to each other by theinsulating rings I1, I2, made of glass.

I claim:-

1. A quartz crystal oscillator comprising a housing completely enclosinga quartz crystal, means for flexibly securing said crystal within saidhousing, said flexible securing means comprising a plurality of springshaving pointed members touching the periphery of said crystal.

2. A quartz crystal oscillator comprising a housing completely enclosinga quartz crystal, means for flexibly securing said crystal within saidhousing, said flexible securing means comprising three springs havingpointed members touching the periphery of said crystal.

3. A quartz crystal oscillator comprising a housing completely enclosinga quartz crystal, means for flexibly securing said crystal within saidhousing, said flexible securing means comprising a plurality of springshaving pointed members secured to a plurality of cone-like apertures onthe periphery of said crystal.

4. A quartz crystal oscillator comprising a housing completely enclosinga disc-like quartz crystal, means for flexibly securing said crystalwithin said housing, said flexible securing means comprising a pluralityof springs having pointed members secured to a circumferential groove onsaid crystalv 5. A quartz crystal oscillator comprising a housingcompletely enclosing a quartz crystal, a heating winding surroundingsaid housing, means for flexibly securing said crystal within saidhousing, said flexible securing means comprising a plurality of springshaving pointed members touching the periphery of said crystal.

6. A quartz crystal oscillator comprising a housing completely enclosinga quartz crystal, means for flexibly securing said crystal within saidhousing, said flexible means comprising a plurality of pointed memberssecured to a leaf spring for pressing said pointed members against theperiphery of said crystal.

7. A quartz crystal oscillator comprising a housing completely enclosinga quartz crystal, a central holding ring secured within said housing,means for flexibly securing said crystal within said housing, saidflexible securing means comprising a plurality of springs having pointedmembers touching the periphery of said crystal. 8. A quartz oscillatorcomprising a housing completely enclosing a quartz crystal, a centralholding ring secured within said housing, a quartz crystal interposedbetween an upper and lower electrode, means for flexibly securing saidcrystal Within said housing, said flexible securing means comprising aplurality of springs having pointed members touching the periphery ofsaid crystal.

9. A quartz oscillator "comprising a housing completely enclosing aquartz crystal, a central holding ring secured within said housing, aquartz crystal interposed between an upper and'lower electrode,insulating rings spacing said electrodes, means for flexibly securingsaidcrystal within said housing, said flexible securing means comprisinga plurality of springs having pointed members touching the periphery ofsaid crystal.

10. A quartz oscillator comprising a housing completely enclosing aquartz crystal, a central holding ring secured Within said housing, aquartz crystal interposed between an upper and lower electrode,insulating rings spacing said crystal and said holding ring from saidelectrodes, means for flexibly securing'said crystal Within saidhousing, said flexible securing means comprising a plurality of springshaving pointed'members touching the periphery of said crystal;

11. A quartz crystal oscillator comprising a support for retaining aquartz crystal, means for flexibly securing said crystal to saidsupport,said flexible securing means comprising a plurality of springs havingretaining members touching the periphery of said crystal. 7

12. A quartz crystal oscillator comprising a support for retaining aquartz crystal, means for flexibly securing said crystal to saidsupport, said flexible securing means comprising a plurality ofretaining members touching the periphery of said crystal, at least oneof which comprises a spring.

13. A quartz crystal oscillator comprising a support for retaining aquartz crystal, means for flexibly securing said crystal to saidsupport, said flexible securing means comprising a plurality ofretaining members touching the periphery of said crystal, at least oneof which comprises a laminated spring.

14. A quartz oscillator comprising a housing en- 1 closing a quartzcrystal, a holding ring secured within said housing, ,a quartz crystalinterposed between an upper and lower electrode, insulating ringsspacing said electrodes, means for flexibly securing said crystal withinsaid housing, said enclosing a quartz crystal, a holding ring securedwithin said housing, a quartz crystal interposed between an upper andlower electrode, insulating rings spacing said electrodes, means forflexibly securing said crystal within said housing, said flexiblesecuring means comprising a plurality of retaining members touching theperiphery of said crystal, at least one of Which comprises a'spring.

16. A quartz oscillator comprising a housing enclosing a quartz crystal,a holding ring secured within said housing, a quartz crystal interposedbetween an upper and lower electrode, insulating rings spacing saidelectrodes, means for flexibly securing said crystal within saidhousing, said flexible securing means comprising a plurality ofretaining members touching the periphery of said crystal, at least oneof which comprises a laminated spring.

RUDOLF BECHMANN.

